Clamp jaw



April 9, 1929. J. M. HARGRAVE CLAMP JAW Filed OCT.. 29, 1927 atto: luk

Patented Apr. 9, 1929.`

PATENT OFFICE.

UNiTEDfs-TATES .ioniv ivi. HARGRAVE, or CINCINNATL- 01110.

CLAMP JAW.

.eppiicaeion sied eclater 29,1927. serial No'. 229,756.

This invention relates to clamp jaws and isparticularly directed to areinforced structure adapted forenibodinient in jaws of substantiallength. A v

For certain types of jaws, such as used in joiners clamps, it isnecessary to have the lworkengaging face of Vthe jaw a sutiicientdistance from the bar on which the slide in order to provide a workingclearance for facile handling and clamping of large objects. Due to vthesubstantial length of theseV jaws, bending and torsional stresses haveresulted in considerable deformation unless the construction has beenvery heavy and the proper metals used. These jaws are'forined of variousmetals, such as cast iron, malleable iron', steel forgings, etc., thebetter grades of metal bein@- expensive and the cheaper gradesnecessitating considerable material to provide strength and, therefore,being extremely heavy. l c

llt is an object of this invention to provide trussed jaw of lightconstruction adapted to withstand deformation such as might otherwiseresultvfrom bending' and torsional i stresses produced lby heavy,clamping presthe'jaws.

Figure 2 is asectional view taken on line 2 2, Figure 1, detailing aVclamping jaw.

Referring to the drawings, a longitudinal clamp bar is indicated at 1. Apair ofjaws 2, 3 are shown mounted on the bar, the jaw 2 being fixed tothe bar by means of a rivet 4 and t-he jaw 3 being slidable thereon anddisplacement at the end of the bar prevented by a stop rivet 5. Themeans involved in frictionally securing the slidable jaw in clampingposition is not shown herein inasmuch as this invention is directedpurely to the formation of a jawr concerning strength and durabilitytherefor. The relative arthrough the outer end thereof parallel to thebarY 1. An adjustable face 8 is mounted through a ball and socketarrangement on the Vend of the screw andopposes the face 6 of the jaw 3,the work being adapted to be clamped between these faces 6, 8. A wingedhandle 9 is located at the opposite end of the screw 7. Vith theexception of the outer ends, as far as this invention is concerned, thejaws 2 and are identical. That is to say, the trussing and bracing isthe saine in both events so that the description will be appliedgenerally.

' The intermediate portion of a jaw is entirely of ribbedformation,`being outlined by the outer wall l() and inner wall 11, theouter wallconverging and joining to the rear side of the work engagingface in the case of the movable jaw and to the outer end of the boreportion in Vthe case of the stationary jaw. The walls 10 and l1 aresubstantially the saine width as the general jaw thickness and arejoined by a seriesof ribs 12 of the same width. The inner'wall, however,as shown, is slightly widened to Vprovide a reinforcing bead 13extending around the clamp jaw. The ribs 12 are equi-spaced and areparallel with the bar engaging bore of the jaw, forining slightlyirregular rectangular areas. In theV c'ase'of the slidable jaws theoutermost parallel rib 12 may be widened as shown at '14' (see Figure 2)to 0in over a greater area l2 because they extend across rectangles, theribs l2 constituting the long sides ofthe rectangles. Medially disposedWebs 16 are formed at each end of the rectangular boX- like areas atright anglesto the outer Walls and ribs. Y Y

' As a means for visualizing the manner in which the integrally formedribbed structure resists the stresses set up `by external forces appliedto the ,outer end of the jaw, the action on a single boXlike orrectangular area Will bel noted.. The tendency under direct bending, dueto a forceliaving noV torsional etlect but at afdirect angle' totlie'laterally extending Work engaging face, isto 'forcethe corners 1 7Oflthe rectangular area together, spreadingv `apart the opposingcorners, the diagonal rib resisting this tendency and having a tensionalstress setup therein. If the diagonal iib Wereoppositely diagonal itWouldfact as a strut and there would be a. compression stress Setup. g I

Theillus'trated arrangement is the pre-v `ierred form since metal inthin sect-ionvvitlistandstension better than compression. The

. @oppositearrangement, however, is vintended v as Well as collapsing-oftlie-boX-like areas.V

to be Within the bounds'an'd spiritiof this invention and for use inthis type ,ofrei'nforce -Inent.` j

The strength provided in a. particular b'oX-` like construction, assliown,`is multiplied .by

the ,number of these rectangles provided. The reinforcement thuspro-vided also Withstands torsional stressesivhich may be set up by'disalignment Yof the Work during clamp- .'ving. The latterresultmay besaid to occur,

first, from the relation of thediagonally disposed ribs preventingbreaking down or deli! o'rniation'V under directly applied load, and

second, from their Width, preventing twisting 4The tendency, astorsionalstresses are set up in tlieijavv, is to collapse the Wallsl() and 11 AY' of theljaiv, tliis'beijng prevented bythe Wide parallelribsl2'inserted between the Walls at a series of points.

Having 4thus described my invention,

ffl. :An .'integrally Aformed clamping comprising, a mounting end, Valaterally dis my naine.

posed Work engaging 'face at ythe opposite end of saidk aW, an innerWalland an outer Wall of the sainewidtli as the general jaw thicknessand converging to goin to the Work engaging end,y a series'of ribsJoining saidrwalls and disposed parallel to the line of direct thrustsimposed on the Work engaging face, diagonally disposed ribs extendingfrom opposite corners formed by the V]uncture of said parallel ribs andsaid Walls, and Webs disposed at lright angles toY saidparallel ribsandsaid `Walls in the opposing corners from those Vjoined by tlie diagonalribs. Y j i f2.' A nintegrally Aformed clamping jaw,

comprising, a. mounting end, a laterally disposed Woijk engaging face atthe/opposite end,`an` inner Wall and an outer Wall joining disposedV inthe direction of thrust imposed on the Work engaging end, anddiagonal'ribs extending from the lowerinost corners at the Work engagingside of tli'e`jaiv' forined by the juncture'of ribs and Walls totheopposing corner therefrom viii/'hereby said diagonal ribs tensionallytake up the stresses created on the parallel ribs. Y

Ll. A,clampinggawstructure, comprising, a slide'bar engaging end, aivoi'kengagiiig end, an intermediate arm portion having an inner andouter Wall, ribs ]oi'ninn' said Walls, Ysaidfribsdisposed parallel tothe lWork pressure applied to the o uteiivoi'k enga-ging end, `anddiagonally disposed Yribs extending between tlie opposite corners formedby the 'juncture of ribs and inner andouter walls.

' `InWitnesswhereof, hereunto subscribe lioi'iiv M; iiiineipivn,

